serialutilities.java

来自「JfreeChart 常用图表例子」· Java 代码 · 共 488 行 · 第 1/2 页

            }
            else {
                stream.writeObject(stroke.getClass());
                stream.writeObject(stroke);
            }
        }
        else {
            stream.writeBoolean(true);
        }
    }

    /**
     * Reads a <code>Shape</code> object that has been serialised by the 
     * {@link #writeShape(Shape, ObjectOutputStream)} method.
     *
     * @param stream  the input stream (<code>null</code> not permitted).
     *
     * @return The shape object (possibly <code>null</code>).
     *
     * @throws IOException  if there is an I/O problem.
     * @throws ClassNotFoundException  if there is a problem loading a class.
     */
    public static Shape readShape(final ObjectInputStream stream)
        throws IOException, ClassNotFoundException {

        if (stream == null) {
            throw new IllegalArgumentException("Null 'stream' argument.");   
        }
        Shape result = null;
        final boolean isNull = stream.readBoolean();
        if (!isNull) {
            final Class c = (Class) stream.readObject();
            if (c.equals(Line2D.class)) {
                final double x1 = stream.readDouble();
                final double y1 = stream.readDouble();
                final double x2 = stream.readDouble();
                final double y2 = stream.readDouble();
                result = new Line2D.Double(x1, y1, x2, y2);
            }
            else if (c.equals(Rectangle2D.class)) {
                final double x = stream.readDouble();
                final double y = stream.readDouble();
                final double w = stream.readDouble();
                final double h = stream.readDouble();
                result = new Rectangle2D.Double(x, y, w, h);
            }
            else if (c.equals(Ellipse2D.class)) {
                final double x = stream.readDouble();
                final double y = stream.readDouble();
                final double w = stream.readDouble();
                final double h = stream.readDouble();
                result = new Ellipse2D.Double(x, y, w, h);
            }
            else if (c.equals(Arc2D.class)) {
                final double x = stream.readDouble();
                final double y = stream.readDouble();
                final double w = stream.readDouble();
                final double h = stream.readDouble();
                final double as = stream.readDouble(); // Angle Start
                final double ae = stream.readDouble(); // Angle Extent
                final int at = stream.readInt();       // Arc type
                result = new Arc2D.Double(x, y, w, h, as, ae, at);
            }            
            else if (c.equals(GeneralPath.class)) {
                final GeneralPath gp = new GeneralPath();
                final float[] args = new float[6];
                boolean hasNext = stream.readBoolean();
                while (!hasNext) {
                    final int type = stream.readInt();
                    for(int i=0; i<6; i++) {
                        args[i] = stream.readFloat();
                    }
                    switch (type) { 
                        case PathIterator.SEG_MOVETO :  
                            gp.moveTo(args[0],args[1]);
                            break;
                        case PathIterator.SEG_LINETO :                           
                            gp.lineTo(args[0],args[1]);
                            break; 
                        case PathIterator.SEG_CUBICTO :
                            gp.curveTo(
                                args[0], args[1], args[2], 
                                args[3], args[4], args[5]
                            );
                            break;
                        case PathIterator.SEG_QUADTO :
                            gp.quadTo(args[0], args[1], args[2], args[3]);
                            break;                  
                        case PathIterator.SEG_CLOSE :
                            //result = gp;
                            break;
                        default : 
                            throw new RuntimeException(
                                "JFreeChart - No path exists"
                            ); 
                    } 
                    gp.setWindingRule(stream.readInt());    
                    hasNext = stream.readBoolean();
                }
                result = gp;
            }
            else {
                result = (Shape) stream.readObject();
            }
        }
        return result;

    }

    /**
     * Serialises a <code>Shape</code> object.
     *
     * @param shape  the shape object (<code>null</code> permitted).
     * @param stream  the output stream (<code>null</code> not permitted).
     *
     * @throws IOException if there is an I/O error.
     */
    public static void writeShape(final Shape shape,
                                  final ObjectOutputStream stream) 
        throws IOException {

        if (stream == null) {
            throw new IllegalArgumentException("Null 'stream' argument.");   
        }
        if (shape != null) {
            stream.writeBoolean(false);
            if (shape instanceof Line2D) {
                final Line2D line = (Line2D) shape;
                stream.writeObject(Line2D.class);
                stream.writeDouble(line.getX1());
                stream.writeDouble(line.getY1());
                stream.writeDouble(line.getX2());
                stream.writeDouble(line.getY2());
            }
            else if (shape instanceof Rectangle2D) {
                final Rectangle2D rectangle = (Rectangle2D) shape;
                stream.writeObject(Rectangle2D.class);
                stream.writeDouble(rectangle.getX());
                stream.writeDouble(rectangle.getY());
                stream.writeDouble(rectangle.getWidth());
                stream.writeDouble(rectangle.getHeight());
            }
            else if (shape instanceof Ellipse2D) {
                final Ellipse2D ellipse = (Ellipse2D) shape;
                stream.writeObject(Ellipse2D.class);
                stream.writeDouble(ellipse.getX());
                stream.writeDouble(ellipse.getY());
                stream.writeDouble(ellipse.getWidth());
                stream.writeDouble(ellipse.getHeight());
            }
            else if (shape instanceof Arc2D) {
                final Arc2D arc = (Arc2D) shape;
                stream.writeObject(Arc2D.class);
                stream.writeDouble(arc.getX());
                stream.writeDouble(arc.getY());
                stream.writeDouble(arc.getWidth());
                stream.writeDouble(arc.getHeight());
                stream.writeDouble(arc.getAngleStart());
                stream.writeDouble(arc.getAngleExtent());
                stream.writeInt(arc.getArcType());
            }
            else if (shape instanceof GeneralPath) {
                stream.writeObject(GeneralPath.class);
                final PathIterator pi = shape.getPathIterator(null);
                final float[] args = new float[6];
                stream.writeBoolean(pi.isDone());
                while(!pi.isDone()) {
                    final int type = pi.currentSegment(args);
                    stream.writeInt(type);
                    // TODO: could write this to only stream the values
                    // required for the segment type
                    for (int i = 0; i < 6; i++) {
                        stream.writeFloat(args[i]);
                    }
                    stream.writeInt(pi.getWindingRule());
                    pi.next();
                    stream.writeBoolean(pi.isDone());
                }
            }
            else {
                stream.writeObject(shape.getClass());
                stream.writeObject(shape);
            }
        }
        else {
            stream.writeBoolean(true);
        }
    }

    /**
     * Reads a <code>Point2D</code> object that has been serialised by the 
     * {@link #writePoint2D(Point2D, ObjectOutputStream)} method.
     *
     * @param stream  the input stream (<code>null</code> not permitted).
     *
     * @return The point object (possibly <code>null</code>).
     *
     * @throws IOException  if there is an I/O problem.
     */
    public static Point2D readPoint2D(final ObjectInputStream stream)
        throws IOException {

        if (stream == null) {
            throw new IllegalArgumentException("Null 'stream' argument.");   
        }
        Point2D result = null;
        final boolean isNull = stream.readBoolean();
        if (!isNull) {
            final double x = stream.readDouble();
            final double y = stream.readDouble();
            result = new Point2D.Double(x, y);
        }
        return result;

    }

    /**
     * Serialises a <code>Point2D</code> object.
     *
     * @param p  the point object (<code>null</code> permitted).
     * @param stream  the output stream (<code>null</code> not permitted).
     *
     * @throws IOException if there is an I/O error.
     */
    public static void writePoint2D(final Point2D p,
                                    final ObjectOutputStream stream) 
        throws IOException {

        if (stream == null) {
            throw new IllegalArgumentException("Null 'stream' argument.");   
        }
        if (p != null) {
            stream.writeBoolean(false);
            stream.writeDouble(p.getX());
            stream.writeDouble(p.getY());
        }
        else {
            stream.writeBoolean(true);
        }
    }

}